What’s the difference between noise and sound?

Mar 15, 2017 | Blog

Photo Credit: Ketzirah Lesser & Art Drauglis

By Daniel Fink, MD, Chair, The Quiet Coalition

One of the heated discussions that sometimes occurs among those of us concerned about noise is the use of the terms “noise” and “sound.” Some people insist that we hear noise but measure sound. Others say the terms can be used interchangeably.

The word “noise” means “unwanted sound,” with an implication of being bothersome. One dictionary definition of noise is, “a sound, especially one that is loud or unpleasant or that causes disturbance.”  “Sound,” on the other hand, implies meaning, “a particular auditory impression.”

Nina Kraus, Professor of Communication Sciences, Neurobiology, and Otolaryngology at Northwestern University, has written an intriguing article for Scientific American that discusses new research that shows that our brains can actually tell the difference between noise and sound. Studies of brain waves, done at Northwestern, show that sound is understood by the brain while noise merely disrupts it.  And noise not only interferes with function, it can actually damage the brain:

Noise is more pernicious than an in-the-moment nuisance. Even a modest level of noise, over a long enough period of time (e.g. beeping garbage trucks, hair dryers, air conditioners), can cause damage to the brain networks that extract meaning from sound. Many of us don’t even realize our brains are being blunted and our thinking impeded by this invisible force.

So what can we do to protect our brains from damaging noise?  We can’t shut out all sound, because “the absence of meaningful sound also leaves a mark on the ability to process sound.”  Dr. Kraus adds that “there are distinct ways to tone and hone your listening brain.”  Namely:

You can learn a second language. The challenge of juggling two languages bolsters the auditory system and redounds to improvements in cognitive functions such as attention.

Another way to exercise your auditory brain is to play a musical instrument. This has a huge payoff cognitively and emotionally for children and adults alike. A few years of playing an instrument while in school sharpens the auditory system and can benefit language development in children. And this benefit lasts a lifetime.

Fascinating!  Even more supporting evidence for the goal of The Quiet Coalition: to make the world quieter, one decibel at a time.

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